[DevTools] Rework DevToolsSession interaction with domain handlers.

content/browser/devtools/protocol/inspector_handler.cc

Index: content/browser/devtools/protocol/inspector_handler.cc
diff --git a/content/browser/devtools/protocol/inspector_handler.cc b/content/browser/devtools/protocol/inspector_handler.cc
index b333315337a50bc573cedbc2ab37f8a37d0cffc7..10a4306b709ffb8917a5198aceb40d554a496f16 100644
--- a/content/browser/devtools/protocol/inspector_handler.cc
+++ b/content/browser/devtools/protocol/inspector_handler.cc
@@ -4,18 +4,26 @@
 
 #include "content/browser/devtools/protocol/inspector_handler.h"
 
+#include "content/browser/devtools/devtools_session.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 
 namespace content {
 namespace protocol {
 
 InspectorHandler::InspectorHandler()
-    : host_(nullptr) {
+    : DevToolsDomainHandler(Inspector::Metainfo::domainName),
+      host_(nullptr) {
 }
 
 InspectorHandler::~InspectorHandler() {
 }
 
+// static
+InspectorHandler* InspectorHandler::FromSession(DevToolsSession* session) {
+  return static_cast<InspectorHandler*>(
+      session->GetHandlerByName(Inspector::Metainfo::domainName));
+}
+
 void InspectorHandler::Wire(UberDispatcher* dispatcher) {
   frontend_.reset(new Inspector::Frontend(dispatcher->channel()));
   Inspector::Dispatcher::wire(dispatcher, this);